Kinetic modeling of electrodynamic space tethers

Electrodynamic space tethers provide propellant-less orbit boosting and de-orbiting of Low Earth Orbit (LEO) satellites. On the one hand, when driven by a current, their interaction with the Earth's magnetic field creates a thrusting Lorentz force. On the other hand, current can be collected from the ionospheric electrons, which also creates a drag. Although the principle is simple, one theoretical issue still has to be addressed: How much current is collected in realistic LEO conditions by a tether of a given section and potential ? The current theories of current collection fail to explain in-space experimental results and previous kinetic modeling was limited from the computational and physical standpoints: wake partly outside the simulation domain, artificial ion/electron mass ratios, single tether, etc. In the present work we improve our computational techniques and physical model to simulate the tether interaction with the ionosphere. We built a full PIC code which allows to study realistic configurations with the 3V modelling of plasma-probe interactions in external and self-induced magnetic fields. The model uses real electron-ion mass ratio and can simulate domains larger than the wake created in a flowing plasma, thanks to the implementation of a Fast Poisson Solver. Multiwire modelling is available as well to study the interference and efficiency of parallel tether array configurations. The theory of current collection has then been further developed, by showing the existence of electron trapping around the probe, and evaluating the consequences on current collection. This analysis was supported and discussed through several simulations ran with the PIC code.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Deux, Jean-Marie A

Advisor dc:contributor.advisor

• Manuel Martínez-Sanchez and Oleg Batishchev.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/32451

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32451